app/views/shopping_lists/

_form.html.erb

<%= form_with(model: shopping_list, class: "mb-7") do |form| %>
    <div class="mb-5">
        <%= form.text_field :title, placeholder: "Create new shopping list", class: "placeholder:italic placeholder:text-slate-400 block bg-white w-full border border-slate-300 rounded-md py-2 px-2 shadow-sm focus:outline-none focus:border-sky-500 focus:ring-sky-500 focus:ring-1 sm:text-sm" %>
        <%= form.submit "Save", class: "bg-sky-500 hover:bg-sky-600 active:bg-sky-700 focus:outline-none focus:ring focus:ring-sky-300 rounded-md py-2 px-9 mt-8" %>
    </div>
<% end %>

_shopping_list.html.erb

<div class="flex m-2">
    <%= shopping_list.title %>
</div>

index.html.erb

<div class="flex-col w-1/2">
    <h1 class="font-bold text-xl">Shopping Lists</h1>

    <div class="mt-8">
        <%= render "form", shopping_list: @shopping_list %>
    </div>

    <%= render @shopping_lists %>
</div>
<div class="flex-col w-1/2">
</div>